1. Field of the Invention
The present invention is generally directed to memory, and more particularly to implementing a reset function in a non-volatile Static Random Access Memory (nvSRAM) cell or array.
2. The Relevant Technology
Semiconductor memory devices are widely used in the computer and electronics industries as a means for retaining digital information. A typical semiconductor memory device is comprised of a large number of memory elements, known as memory cells, that are each capable of storing a single digital bit. The memory cells are arranged into a plurality of separately addressable memory locations, each being capable of storing a predetermined number of digital data bits. All of the memory cells in the device are generally located upon a single semiconductor chip which is contacted and packaged for easy insertion into a computer system.
The issue of producing a resettable semiconductor memory, which involves using a single command to write all “0”s or all “1”s into every memory location, has been frequently discussed. The most straightforward design approach to achieve this in an SRAM is to bring all word lines high, which consequently requires a significant amount of design and silicon overhead to control the very high current surges associated with moving large values of capacitance. Other methods have been employed using flags to output a high or low state when a given section of memory is addressed. In such devices, the individual memory cells are not immediately altered. Particular methods of resetting semiconductor memory are described in U.S. Pat. No. 5,212,663 to Leong, et al. and in U.S. Pat. No. 6,038,176 to Shyn et al.
It would therefore be advantageous to provide a method and apparatus for producing a resettable semiconductor memory without utilizing additional silicon overhead and without providing additional circuitry to control the maximum chip current.